1. Field of the Invention
This invention relates to the damper actions of upright pianos. A damper action is a mechanism that transmits motion from a piano key and/or motion from a piano pedal into motion of a damper resting on a piano string located inside the piano. In every piano, there is one damper action per piano key, where there are typically 88 piano keys in a piano. When a piano key is at rest, the corresponding damper of the corresponding damper action rests on or presses down onto the corresponding piano string(s), thereby preventing the string(s) from vibrating or making sound. When the piano key is depressed, the damper action causes the damper to lift off of the piano string(s), thereby allowing the string(s) to vibrate and to make sound. When the piano key is released, the damper action causes the damper to return to the rest position, pressing back onto the piano sting(s), thereby dampening the vibrations and eliminating the sound of the piano string(s). Alternately, damper actions may be actuated to lift dampers by depressing the sustain pedal or by depressing the sostenuto pedal of the piano. When the sustain pedal or the sostenuto pedal is depressed, one or more dampers is lifted from the piano strings to allow the strings to vibrate without dampening. When the sustain pedal or the sostenuto pedal is released, the damper is returned to the rest position to press down onto the piano strings dampening the sound therefrom. This invention specifically relates to one subcomponent of a damper action, namely the sostenuto tab or sostenuto lip located on the damper lever.
2. Description of Related Art
A damper action comprises: a damper lever, a damper spring, a damper wire, and a damper. A damper action cycles with a key depression, a sustain pedal depression, or a sostenuto pedal depression, where each causes the damper lever to rotate, to move the damper wire attached to one end of the damper lever, which rotates the damper attached to the other end of the damper wire. This causes the damper to be lifted away from the piano strings to allow vibrations and sounds to sustain on the piano strings without dampening by the damper. When the key, sustain pedal, or sostenuto pedal is released, the damper lever returns to the rest position thereby returning the damper to press back against the piano strings. The damper spring puts tension on the damper lever to cause the damper to press against the piano strings when the damper action is at rest. Thus, the damper spring causes the damper to return to the rest position on the piano strings when the piano key is released.
There are three possible ways to actuate a damper action: key depression, sustain pedal depression, and sostenuto pedal depression.
When a piano key is depressed, this causes rotation of the corresponding damper lever, which removes the correspond damper from the corresponding piano strings. When the key is released, the damper lever cycles back to cause the damper to rest back on the piano strings. Thus, one key depression actuates one damper action.
When the sustain pedal is depressed, this causes a sustain lifter rod to rotate, which causes all 88 damper levers in the piano to rotate, thereby removing all 88 dampers from the piano strings. Thus, one sustain pedal depression actuates all 88 damper actions.
When the sostenuto pedal is depressed, this causes all damper actions already actuated from key depression at the time the sostenuto pedal was depressed, to remain detached from the piano strings, even after the formerly depressed keys are released, as long as the sostenuto pedal is held depressed. Depressing the sostenuto pedal allows piano stings to continue to make sound after the corresponding keys are released and to continue to do so until the sostenuto pedal is released. Thus, the sostenuto pedal suspends the return of certain dampers until the sostenuto pedal is released. When the sostenuto pedal is released, the respective dampers return to press back against the piano strings and to dampen the sound produced therefrom.
As discussed in detail below, when the sostenuto pedal is depressed, this causes a sostenuto rod to rotate. When the sostenuto rod rotates, a longitudinal ridge on the sostenuto rod aligns with a tab on the damper levers, to prevent the damper levers from rotating back to the rest position after the key is released.
A problem arises at this point regarding the ability to play other piano keys while holding the sostenuto pedal in the depressed position. As discussed in detail below, depressing a key and actuating a damper action while the sostenuto pedal is depressed causes the tab on the corresponding damper lever to interfere with the longitudinal ridge on the sostenuto rod to produce a clicking sound from the two parts contacting each other, or, even worse, to disrupt the tone of the strings from erratic damper movement caused by the two parts colliding with each other. Thus, there is a problem playing other piano keys while holding the sostenuto pedal down.
The same problem arises when the sostenuto pedal is released. If a key is depresses just as the sostenuto pedal is released, this also causes the tab on the corresponding damper lever to interfere with the longitudinal ridge on the sostenuto rod to produce a clicking sound from the two parts contacting each other, or, even worse, to disrupt the tone of the strings with erratic damper movement caused by the two parts colliding with each other. Similarly, when the sostenuto pedal is released while holding down later depressed keys, the longitudinal ridge on the sostenuto rod interferes with the tab on the corresponding damper lever to produce a clicking sound from the two parts contacting each other or even worse to disrupt the tone of the strings from erratic damper movement caused by the two parts colliding with each other. Thus, there is a problem releasing the sostenuto pedal while play or holding other piano keys.
To remedy these problems, this invention provides a spring tab on the damper lever that “ratchets” or gives way or folds away in one direction and does not in the other, to provide retention when the spring tab passes by the longitudinal ridge on the sostenuto rod in one direction and non-retention when the spring tab passes by the longitudinal ridge on the sostenuto rod the other direction. Further, as discussed below, the ratchet aspect of the spring tab uses tension from the damper spring and does not require a separate spring to apply tension to yield the ratchet effect.
There are no upright piano damper actions in the prior art with spring tabs on the damper levers. There are no upright piano damper actions in the prior art with ratcheted tabs on the damper levers that hold tension from the existing damper spring of the damper action.